Connector

ABSTRACT

A connector for making electrical connection between an externally jacketed conductive shield on a communication cable and a conductor. The vise-like connector includes a pair of resilient opposed plate-like jaws formed with barbs along tapered projecting portions and adapted to be clamped in engagement with an end of the externally jacketed shield.

0 United States Patent 11 1 1111 3,778,749 Kapell 1 Dec. 11, 1973 [54]CONNECTOR 3,676,836 7/1972 Gillemot et al. 174/78 ux 3,701,839 10/1972 S'th 174 78 [75] Inventor: Henry Kapell Mahtomed" 3,253,247 5/1966 V E;174/78 u)! R 73 Assignee; Minnesota Mining and 3,388,367 6/1968 Brown339/97 P X Manufacturing Company, St. Paul, OTHER PUBLICATIONS Herr etal., German Printed Pat. Application No. 22 Filed; 2 1971 1122,583,printed May 3, 1956. [21] Appl' 194,879 Primary Examiner-Darrell L. ClayAttorney-Alexander, Sell et al. [52] U.S. Cl. 339/97 R, 174/78, 174/88 R51 1m. 01 H0lr 9/06, H02g 15/08 ABSTRACT [58] Field of Search 174/78, 88R; A connector for making electrical connection between 339/95 R, 95 P,97 R, 97 P, 98, 99; 24/125 an externally jacketed conductive shield on acommu- R, 85 R, 87 R, 243 B, 243 FS, 263 A, 263 nication cable and aconductor. The vise-like connec- LS, 259 PS tor includes a pair ofresilient opposed plate-like jaws formed with barbs along taperedprojecting portions [56] References Cited and adapted to be clamped inengagement with an end UNITED STATES PATENTS of the externally jacketedshield. 3,594,691 7/1971 Neal 174/78 X 4 Claims, 6 Drawing FiguresPAIENIEDUEBI 1 I975 F/qf mum me K/QPEL 1.

CONNECTOR BACKGROUND OF THE INVENTION This invention relates toelectrical connectors of the type disclosed in U.S. Pats. No. 3,499,972,3,253,247 and 3,594,691 for making an electrical connection between aconductor and the conductive shield on a communication cable.

A communication cable commonly comprises a number of individuallyinsulated wires which may be bound together with an electricallyinsulating inner sheath, a sleeve-like electrically conductive shieldaround the wires, and an electrically insulating outer jacket over theshield. When splicing or terminating the wires, a reliable electricalconnection must be made between a conductor and the conductive shield tocarry an electrical path across the splice or connect the shield to asource of ground potential to afford grounding of currents fromextraneous electrical fields such as lightning.

Some prior art connectors for making such a connector which providepositive mechanical clamping to engage the connector with the conductiveshield have required time consuming preparation of the conductive shieldor outer jacket, such as notching the conductive shield and jacket asrequired for use of the connector disclosed in U.S. Pat. No. 3,499,972,or stripping a portion of the outer jacket from about the conductiveshield as required for use of the connector disclosed in U.S. Pat. No.3,253,247. The connector disclosed in US. Pat. No. 3,594,691 includes anelongate plate-like contact member formed with in-line rows of spursprojecting from a contact surface and angled toward a first end of thecontact member. This connector is attached to a shield by positioningthe contact member beneath the conductive shield with the spurs incontact therewith, pulling the first end of the member to draw the spursinto contact with the conductive shield, and maintaining the contact bybending the'first end of the contact member about the end of theconductive shield. This connector, however, does not afford mechanicalclamping to maintain positive contact between the spurs and theconductive shield.

SUMMARY OF THE INVENTION A connector according to the present inventionprovides and maintains a mechanically strong and electrically efficientgrounding connection with a jacketed section of an electricallyconductive shield on a communication cable without the time consumingpreparation of the shield or jacket. The vise-like connector includes aresilient conductive plate-like first jaw having a tapered projectingportion which may be inserted beneath the conductive shield of acommunication cable. The projecting portion is formed along itsconverging edges with a series of barbs oriented for engagement with theinner surface of the conductive shield to effect an efficient electricalconnection and the points of the barbs project away from the smaller endto restrict extraction of the first jaw. The connector also includes aresilient second jaw having a projecting portion for contacting theouter surface of the jacket surrounding the shield. The connectorincludes clamping means for clamping the jaws in opposed relationship onthe end of the jacketed conductive shield. The clamping means slightlydeforms the resilient jaws so that an electrically efficient andmechanically strong connection will be maintained despite slightdeformation of the jacket caused by continued application of theclamping force.

BRIEF DESCRIPTION OF THE DRAWING The invention will be further describedwith reference to the accompanying drawings wherein like numbers referto like parts in the several views, and wherein:

FIG. 1 is a horizontal view of a connector according to the presentinvention shown attached between a conductor and a jacketed section ofthe conductive shield of a sectioned communication cable fragment;

FIG. 2 is a fragmentary vertical sectional view partially in section ofa pair of connectors according to the present invention each shownattached to a woven conductor and to a jacketed conductive shieldsection on separate communication cables to provide a continuouselectrical path for the shields over a splice between the cables;

FIG. 3 is a horizontal plan view of a connector according to the presentinvention;

FIG. 4 is a bottom view of the connector shown in FIG. 3;

FIG. 5 is a right end view of the connector shown in FIG. 3; and

FIG. 6 is a perspective, exploded view of a connector according to thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2,there is illustrated a connector 10 according to the present invention.The connector 10 is shown engaged with an end of a conductive shield 12and outer jacket 14 of a communication cable 16 to afford electricalcontact between the conductive shield 12 and a woven conductor 18. Theconductor 18 may be attached to a source of ground potential or may be aportion of an electrical path around a splice between separate lengthsof communication cable 16 as shown in FIG. 2.

The communication cable 16 comprises a series of individually insulatedwires 20 which may, as illustrated, be surrounded by an electricallyinsulating inner sheath 22, a sleevelike conductive shield 12 around thewires 20 and inner sheath 22, and the electrically insulating tubularouter jacket 14.

The connector 10, best seen in FIGS. 3 through 6 is vise-like comprisinga pair of resilient elongate platelike jaws 28 and 30 each having aprojecting portion 32 and 34 respectively adapted for engagement inaligned opposed relationship with a jacketed section of the conductiveshield 12. The connector 10 includes clamping means or a bolt 36 and anut 38 for connecting the jaws 28 and 30 together and to the conductor18, and for pressing the projecting portions 32 or 34 into contact witha section of the jacketed conductive shield to slightly deflect theresilient jaws 28 and 30 so that firm clamping engagement will bemaintained despite changes that may occur in the thickness of thejacketed conductive shield section engaged by the clamp 10.

The projecting portion 32 of the first jaw 28 is designed for insertionaxially beneath the conductive shield 12 of a communication cable 16 atan end of the conductive shield 12, for affording efficient electricalconnection between the jaw 28 and the shield 12 and for restrictingremoval of the jaw 28 subsequent to insertion.

The jaw 28, best seen in FIGS. 4 and 6 is formed of a resilient highlyconductive metal such as one-half hard cartridge brass orberyllium-copper. The jaw 28 has a base portion 40 to which the bolt 36may be anchored as by staking. The base portion 40 is slightly curvedabout a lengthwise axis to conform to the contour of the inner sheath22. The projecting portion 32 is symmetrically tapered along its lengthto a smaller generally pointed end 42 and defines a contact surface 44.The contact surface 44 is adapted for engagement with the inner surfaceof the shield 12. A multiplicity of barbs 46 are formed along theconverging edges of the projecting portion 32. Each barb 46 is curved toprotrude from the contact surface 44 with the points of the barbs 46being directed generally away from the end 42. The barbs 46 affordpiercing engagement with a conductive shield 12 to insure efficientelectrical connection therewith despite coatings such as oxides or thethin layer of polyethylene often present on the shield 12. Theconfiguration of the projecting portion spaces the barbs 46 with respectto the width of the jaw 28. Upon insertion of the projecting portion 32beneath a conductive shield 12, the point of each barb 46 will .trace aseparate line of contact against the shield 12 due to the biasingtypically caused by the snug fit of the wires 20 and any inner sheath 22within the shield 12. This affords piercing by the barbs 46 ofprotective coatings or oxides on the shield 12 while restricting gougingof the shield 12 as might occur upon passage of successive barbs alongthe same line of contact. The projecting portion 32 may also be formedwith a series of transversely extending ridges 48 along the surface 44to afford a slight filing of the inner surface of the conductive shieldupon insertion of the projecting portion 32 to remove coatings or oxidesand afford good electrical connection. The projecting portion 32 isslightly curved about a transverse axis to provide a cylindricallyconcave contact surface 44 so that the barbs 46 and contact surface 44will attain full length engagement and generally uniform pressurecontact with the inner surface of the conducting shield 12 upondeflection of the jaw 28 when the connector is clamped onto a jacketedconductive shield section.

The projecting portion 34 of the second jaw 30 is designed forengagement with the exterior surface of the outer jacket 14, in alignedopposed relationship with the contact surface 44 of the first jaw 28.

The jaw 30, best seen in FIGS. 3-6 is formed of a resilient materialsuch as one-half hard brass or stainless steel. The jaw 30 is similar instructure to the jaw 28, having a base portion 50 formed with an opening52 to receive the bolt 36. The projecting portion 34 is symmetricallytapered to a smaller end 56 and defines a contact surface 54 adapted forengagement with the outer surface of the jacket 14 on a communicationcable 12. A multiplicity of barbs 58 are formed along the convergingedges of the projecting portion 34. The barbs 58 are curved to protrudefrom the contact surface 54 with the points of the barbs 58 directedaway from the smaller end 56. This positioning of the barbs 58 affordspiercing engagement of the barbs 58 with the outer surface of the jacket14 torestrict removal of the jaw 30 by longitudinal forces appliedtoward the base portion 50.

The projecting portions 32 and 34 are generally the same length,however, the projecting portion 34 of the second jaw 30 overlaps theprojecting portion 33 of the first jaw 28 along each converging edge byapproximately the width of the barbs 58 on the second jaw 30. Thisoverlap insures that a section ofjacketed shield 12 to which theconnector 10 is attached will be pressed around each barb 46 on thefirst jaw 28 to insure complete electrical contact.

The jaw 30 is generally domed with a concave contact surface 54. The jaw30 is curved about a transverse axis, and about a lengthwise axis toconform to the periphery of the outer jacket 14. This configuration 7provides high structural strength for the projecting portion 34 and fulllength engagement between the contact surface 54 and the jacket 14 upondeflection ofthe projecting portion 34 when the connector 10 is attachedto a section of a jacketed conductive shield 12. The material of the jaw30 is resilient to maintain firm engagement with the outer jacket 14despite deformation of the jacket which may occur due to prolongedclamping pressure.

The barbs 46 and 58 are formed on the jaws 28 and 30 by a multiplicityof linear spaced slits oblique to and extending inwardly from theconverging edges of the projecting portions 32 and 34. Each slit formsan angle (preferably in the range of 15 to 45) with a converging edge todefine a triangular barb 46 or 58. Each barb is curved to protrude fromthe contact surface of the projecting portion 32 or 34 with the point ofthe barb directed away from the smaller end 42 or 56 of the projectingportion. Jaws formed with barbs of this type have been found to havesurprisingly high resistance to fracture starting at the slits formingthe barbs upon application of high clamping forces, apparently due to afavorable orientation of the slit ends with respect to the bendingforces in the jaws. Additionally, the barbs along the converging edgeson each jaw are spaced with respect to the longitudinal axis of theprojecting portion 32 or 34 so that barbs will not be positionedopposite each other on a jaw which would substantially reduce the crosssectional area and strength of the projecting portion. The barbs 28 or30 are preferably formed in spaced relationship along correspondingedges of the projecting portions 32 and 34 to position the barbs on eachjaw generally in the interstice between the barbs on the opposing jaw.This configuration aids in pressing the shield 12 about the barbs 46 onthe first jaw 28, and insures that slight misalignment of the jaws 28and 30 will not result in interference between opposing barbs 46 and 58.

The conductor 18 is illustrated as a braided stranded cable, however,the conductor may also comprise a solid or stranded circular wireattached via a suitable terminal lug to the connector 10. The conductor18 or terminal lug is positioned over the bolt 36 between the baseportion 40 and 50 of the jaws 28 and 30. The conductor 18 or lug shouldhave generally the same compressed thickness as the thickness of thejacketed shield section to which the connector is to be attached toinsure proper deflection of the jaws upon tightening of 42 with a 1/16inch radius. The projecting portion 34 of the second jaw 30 is slightlywider, being approximately 1% inch wide adjacent the base portion 48 andtapered over its 1 inch length to a A inch wide end 39. Each barb 46 or58 on the jaws 28 or 30 is formed by making a 0.2 inch long slitoriented at approximately 30 to the edge of the jaw. Each jaw is curvedwith a 3 inch radius about a transverse axis, and the second jaw 30 iscurved about a longitudinal axis with a inch radius to form a concavecontact surface 54. Connectors of this construction securely connectedbetween ajacketed conductive shield section of a communication cable anda conductor 18 of braided stranded copper cable of 6 gauge equivalenthave consistently met the portion of Automatic Electric CompanyRequirement No. AE 8363 for grounding jumper clip assemblies calling for1200 ampere current flow for 10 seconds with no more than a 5 milliohmincrease in contact resistance.

I claim:

1. A connector for making electrical connection between a conductor anda jacketed electrically conductive shield on a communication cable, saidconnector comprising:

a resilient plate-like conductive first jaw having a base portion, and arelatively flexible elongate symmetrically tapered projecting portionextending from said base portion and terminating in a smaller end, saidelongate projecting portion being arcuate about an axis transverse tothe width thereof to form a cylindrically concave contact surfaceadapted for engagement with the inner surface of said shield and havinga multiplicity of linear spaced slits oblique to and extending inwardlyfrom its converging edges to form triangular barbs, with each of saidbarbs being curved to protrude from said contact surface with the pointthereof directed generally away from said smaller end;

a resilient plate-like second jaw having a base portion, and an elongatesymmetrically tapered projecting portion extending from said baseportion and terminating in a smaller end, the projecting portion of saidsecond jaw being domed to define a concave contact surface adapted forengagement with the outer surface of the jacket on said communicationcable in aligned opposed relationship with said contact surface of saidfirst jaw and having a multiplicity of linear spaced slits oblique toand extending inwardly from its converging edges to form triangularbarbs, with each of said barbs being curved to protrude from saidconcave contact surface with the point thereof directed generally awayfrom the smaller end, the projecting portion of said second jaw being ofessentially the same length as the projecting portion of said first jawand being sufficiently wide to extend over the projecting portion ofsaid first jaw along each converging edge by approximately the width ofsaid barbs formed on said second jaw; and

means coupled only between said base portions for connecting said firstjaw to said conductor and to said second jaw, and for pressing said jawsinto contact with a section of the jacketed shield to engage said barbsand to deflect the projecting portion of said first jaw.

2. A connector useful in making an electrical connection between aconductor and a jacketed electrically conductive shield on acommunication cable, said connector comprising:

a resilient plate-like conductive first jaw having a base portion and arelatively flexible elongate tapered projecting portion extending fromthe base portion and terminating in a smaller end, said elongateprojecting portion being arcuate about an axis transverse to the widththereof to form a cylindrically concave contact surface adapted forengagement with the inner surface of said shield and having a pluralityof spaced slits formed along each edge and extending inwardly from saidedges away from the base portion at an angle of between 15 to 45 withthe edge to form triangular barbs, with each of said barbs being curvedto protrude from said contact surface with the point thereof directedgenerally away from said smaller end;

a resilient plate-like second jaw having a base portion and a projectingportion extending from the base portion and defining a contact surfaceadapted for engagement with the outer surface of the jacket on saidcommunication cable in aligned opposed relationship with said contactsurface of said first jaw, said projecting portion of said second jawbeing wider than corresponding portions of the projecting portion ofsaid first jaw; and

means coupled only between said portions for connecting said first jawto said conductor and to said second jaw and for pressing said jaws intocontact with a section of the jacketed electrically conductive shield toengage said barbs with said shield and to deflect the projecting portionof said first jaw.

3. The connector of claim 2 wherein the projecting portion of saidsecond jaw is tapered toward a smaller end opposite the base portionthereof, and has a multiplicity of linear spaced slits oblique to andextending inwardly from its converging edges to form triangular barbspositioned along its converging edges, each of said barbs being curvedto protrude from said contact surface with the point thereof directedgenerally away from said smaller end; and the projecting portion of saidsecond jaw is wider than the corresponding projecting portion of saidfirst jaw by approximately the width of said barbs formed on said secondjaw.

4. The connector of claim 4 wherein the barbs on said first and secondjaws are formed in spaced relationship along corresponding edges toposition the barbs on each jaw generally in the interstice between barbson the opposing jaw.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 37787u9 'Dated December 973 Inventor(s) Henry K. Kapell It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

:Claim H, line 1, change "claim H" to claim 3 Signed and sealed this 9thday of April 197g.

(SEAL) Attest:

EDL-IARD BLFLETGHERJR. C. MARSHALL DANN Attesting Officer Commissionerof Patents F mm PC1-1050 110-69! UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION 3,77 ,7 9 Dated December 11, 1973 Patent No.

Inventor(s) Henry K. Kapell It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Claim l, line 1, change "claim l" to claim 3 Signed and sealed this 9thday of April 19%..

(SEAL) Attest:

EDWARD JLFUETCHERJR. C. MARSHALL DANN Attesting Officer- Connnissioner'of Patents

1. A connector for making electrical connection between a conductor anda jacketed electrically conductive shield on a communication cable, saidconnector comprising: a resilient plate-like conductive first jaw havinga base portion, and A relatively flexible elongate symmetrically taperedprojecting portion extending from said base portion and terminating in asmaller end, said elongate projecting portion being arcuate about anaxis transverse to the width thereof to form a cylindrically concavecontact surface adapted for engagement with the inner surface of saidshield and having a multiplicity of linear spaced slits oblique to andextending inwardly from its converging edges to form triangular barbs,with each of said barbs being curved to protrude from said contactsurface with the point thereof directed generally away from said smallerend; a resilient plate-like second jaw having a base portion, and anelongate symmetrically tapered projecting portion extending from saidbase portion and terminating in a smaller end, the projecting portion ofsaid second jaw being domed to define a concave contact surface adaptedfor engagement with the outer surface of the jacket on saidcommunication cable in aligned opposed relationship with said contactsurface of said first jaw and having a multiplicity of linear spacedslits oblique to and extending inwardly from its converging edges toform triangular barbs, with each of said barbs being curved to protrudefrom said concave contact surface with the point thereof directedgenerally away from the smaller end, the projecting portion of saidsecond jaw being of essentially the same length as the projectingportion of said first jaw and being sufficiently wide to extend over theprojecting portion of said first jaw along each converging edge byapproximately the width of said barbs formed on said second jaw; andmeans coupled only between said base portions for connecting said firstjaw to said conductor and to said second jaw, and for pressing said jawsinto contact with a section of the jacketed shield to engage said barbsand to deflect the projecting portion of said first jaw.
 2. A connectoruseful in making an electrical connection between a conductor and ajacketed electrically conductive shield on a communication cable, saidconnector comprising: a resilient plate-like conductive first jaw havinga base portion and a relatively flexible elongate tapered projectingportion extending from the base portion and terminating in a smallerend, said elongate projecting portion being arcuate about an axistransverse to the width thereof to form a cylindrically concave contactsurface adapted for engagement with the inner surface of said shield andhaving a plurality of spaced slits formed along each edge and extendinginwardly from said edges away from the base portion at an angle ofbetween 15* to 45 * with the edge to form triangular barbs, with each ofsaid barbs being curved to protrude from said contact surface with thepoint thereof directed generally away from said smaller end; a resilientplate-like second jaw having a base portion and a projecting portionextending from the base portion and defining a contact surface adaptedfor engagement with the outer surface of the jacket on saidcommunication cable in aligned opposed relationship with said contactsurface of said first jaw, said projecting portion of said second jawbeing wider than corresponding portions of the projecting portion ofsaid first jaw; and means coupled only between said portions forconnecting said first jaw to said conductor and to said second jaw andfor pressing said jaws into contact with a section of the jacketedelectrically conductive shield to engage said barbs with said shield andto deflect the projecting portion of said first jaw.
 3. The connector ofclaim 2 wherein the projecting portion of said second jaw is taperedtoward a smaller end opposite the base portion thereof, and has amultiplicity of linear spaced slits oblique to and extending inwardlyfrom its converging edges to form triangular barbs positioned along itsconverging edges, each of said barbs being curved to protrude from saidcontact surface with the point Thereof directed generally away from saidsmaller end; and the projecting portion of said second jaw is wider thanthe corresponding projecting portion of said first jaw by approximatelythe width of said barbs formed on said second jaw.
 4. The connector ofclaim 4 wherein the barbs on said first and second jaws are formed inspaced relationship along corresponding edges to position the barbs oneach jaw generally in the interstice between barbs on the opposing jaw.